Sestak: McChrystal's fate hinges on his necessity

Says McChrystal can keep command if president believes he is necessary for success in Afghanistan

Washington (CNN) -- The highest ranking military officer to serve in Congress said Tuesday that Gen. Stanley McChrystal can retain his command if the president believes that McChrystal is necessary for the success of the Afghan war strategy.

Rep. Joe Sestak, a Democratic congressman from Pennsylvania and former three-star admiral who is now running for Senate, told CNN's "John King, USA" that while McChrystal's actions reported in a magazine article were "cause for dismissal, without a question," it doesn't necessarily mean he will be ousted as head of U.S. forces in Afghanistan.

"If the president believes that he is necessary for the success of this mission," McChrystal might keep his post, Sestak said before criticizing the general's conduct.

"First off, he broke a military code," Sestak said of McChrystal. "You go into a commander-in-chief's room, and if you disagree, you keep it there. And that means the same for the men and women who work for you. You don't go out and say you don't like the cut of his jib."

On the eve of McChrystal's scheduled meeting with President Barack Obama, Sestak said the president will have to weigh the consequences of replacing his Afghan commander.

"The issue is not the policy difference. This general has been over there fighting both in Iraq and this war. It gets pretty tough at times and there is some venting that shouldn't have been done," Sestak said. "But this president, this commander-in-chief, who supported this policy that this general wanted, has to make his decision."

When asked whether a change in command would impact the war effort, Sestak said there would be a hiccup just as the military gears up for a crucial offensive in the Kandahar valley.

"I think there would be a step that would be missed, because Kandahar as you know, we are going into this offensive, and it's a very important moment," Sestak said.